Unmanaged array
equi...@att.net
The following code block defines several types in VBA.
Public Type ProbParamKind
Na As Long
Nc As Long
Nstep As Long
MaxCycles As Long
AxialPts As Long
End Type
Public Type RunOptKind
KeyProdID As Long
KeyImpID As Long
KeyProdSpec As Double
KeyImpSpec As Double
RecoveryTarget As Double
PurgeFactor As Double
CoCurCutOff As Double
BedSizeFactor As Double
BedVol As Double
BedLen As Double
TempWall As Double
NonAdiabaticFrac As Double
ISOmodel(1 To 8) As Byte 'Array of bytes representing IsoModel As
String * 8
End Type
Public Type GasKind
GasID(1 To 8) As Byte 'Array of bytes representing GasID As
String * 8
Mw As Double
CpPar(1 To 4) As Double
MuPar(1 To 2) As Double
LmdaPar(1 To 3) As Double
End Type
It makes a call to a fortran dll using arrays of these types and a
long to return an error code.
Public Declare Sub PSAEngine Lib "PSAxEngine.dll" ( _
ProbParam As ProbParamKind, RunOpt As RunOptKind, _
Gases As GasKind, ByRef errFlag As Long)
It works fine.
I have defined these structures in VB DotNet that match the types in
VBA
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi)> Public
Structure ProbParamKind
Dim Na As Int32
Dim Nc As Int32
Dim Nstep As Int32
Dim MaxCycles As Int32
Dim AxialPts As Int32
End Structure
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi)> Public
Structure RunOptKind
Dim KeyProdID As Int32
Dim KeyImpID As Int32
Dim KeyProdSpec As Double
Dim KeyImpSpec As Double
Dim RecoveryTarget As Double
Dim PurgeFactor As Double
Dim CoCurCutOff As Double
Dim BedSizeFactor As Double
Dim BedVol As Double
Dim BedLen As Double
Dim TempWall As Double
Dim NonAdiabaticFrac As Double
<MarshalAs(UnmanagedType.ByValArray, SizeConst:=8)> Dim
ISOmodel() As Byte
End Structure
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi)> Public
Structure GasKind
<MarshalAs(UnmanagedType.ByValArray, SizeConst:=8)> Dim
GasID() As Byte
Dim Mw As Double
<MarshalAs(UnmanagedType.ByValArray, SizeConst:=4)> Dim
CpPar() As Double
<MarshalAs(UnmanagedType.ByValArray, SizeConst:=2)> Dim
MuPar() As Double
<MarshalAs(UnmanagedType.ByValArray, SizeConst:=3)> Dim
LmdaPar() As Double
End Structure
Here is the dotnet call definition
Public Declare Sub PSAEngine Lib "PSAxEngine.dll" ( _
ByRef ProbParam As ProbParamKind, ByRef RunOpt As RunOptKind,
_
ByRef Gases As GasKind, ByRef errFlag As Int32)
Here is the call in code
Call PSAEngine(ProbParam, RunOpt, Gases(0), errFlag)
When I try to use the same fortran dll with matching arrays, I get
junk after the first element of the array of GasKind.
Gases is loaded correctly with 10 elements in the code before the
call.
The first element contains the data I set to be passed in. Starting
with the second element, elements contain jibberish (and it differs
from one execution to the next I might add so I don't think it is just
a shift of position).
Can anyone give me a hint as to what I have missed?
I think the second element of the GasKind array is being read from the
wrong memory address but I can't tell why.